Many types of vaginal discharge are normal and not indicative of any infection. When a woman detects what she suspects is an abnormal discharge she may wait to see if it goes away or she may try to treat herself using readily available over-the-counter remedies before visiting her physician for treatment. Delaying treatment or self treatment often results in an exacerbation of the infection.
Similarly, vaginal itching, while not normal, is not necessarily indicative of any infection. When a woman detects vaginal itching, however, she suspects an infection and usually seeks medical attention immediately. Frequently, the itching is due to an allergy or physical irritation rather than an infection. Because bath soap is the most common cause of such irritation many times no specific treatment is necessary. If the cause of the itching is not an infection, the condition is likely to be resolved spontaneously or through minor self treatment.
It is well known among physicians to confirm the presence of an infectious organism through the use of a variety of culture techniques. One well known technique involves inserting a cotton swab into the vagina, picking up inoculum in vaginal secretion on the swab and transferring the inoculum to a tube or petri plate containing culture medium. The plate or tube is then incubated and examined for the black or brown spots that are characteristic of yeast colonies and indicative of a yeast infection. This technique has a number of drawbacks:
(1) Much of the vaginal secretion that contacts the cotton swab is absorbed by the bottom fibers and the inoculum is not transferred to the culture medium. This decreases the sensitivity of the test. In fact so little yeast may be transferred that the characteristic colonies develop slowly, if at all, and are difficult even for trained personnel to identify.
(2) Some training is necessary to properly insert the swab into the vagina and properly transfer the inoculum to the surface of the culture medium. While not complicated, this procedure is not suitable for home use.
(3) The culture media is grayish, as are developing yeast colonies. The growing colonies are thus gray on gray, which makes it difficult for someone without experience reading cultures to pick out developing colonies on the surface of the media.
It is also well known to use a metal speculum in place of the cotton swab to transfer the vaginal secretion to the culture medium. The metal speculum increases the sensitivity of the test because much of the inoculum will eventually be transferred to the culture medium. But this advantage is more than offset by the increased cost and the amount of skill necessary to use it. Swabbing with a metal speculum also carries some risk of inadvertent laceration of the vaginal wall. In addition, the speculum must be sterilized professionally and cannot be self inserted.
U.S. Pat. No. 3,368,549 teaches replacing the cotton swab with a globule of molded culture medium, or molding a globule of culture medium over a cotton swab. This device is theoretically simpler than traditional techniques because the culture medium contacts the inoculum directly. This device is not usable, however, because of the following serious disadvantages: The inoculum is heavily concentrated in one area and the culture medium is extremely dense, because the colonies cannot penetrate the medium, even after prolonged growth, they appear as small, concentrated spots that are difficult to see without magnification, thus making the results difficult to evaluate. Also, the swab is too short and too sharp to be usable in the vagina where it could easily cause laceration.
U.S. Pat. No. 3,616,265 teaches a flattened, elongated support which carries culture medium. The support fits into a companion container that has brushes positioned over its open end. In use, the support is used to pick up inoculum directly and when the support is inserted in its companion container the brushes contact the medium and spread the inoculum out on the culture medium. Because the brushes must be positioned to brush the media at the correct level, this device is complex and expensive to manufacture. Additionally, the support is hard like a speculum and swabbing must be performed carefully.
U.S. Pat. Nos. 4,653,510 and 4,485,824 both teach using swab elements enclosed in companion tubes that can contain culture media. The tube, which contains either a cotton wadding swab element or one of firmly wound rayon filament, is inserted in the vagina where the swab element is extended from the tube to pick up the inoculum. Retracting the swab element back into the tube brings the inoculum into contact with the media. This device is also complex with close tolerances between its parts. The media is dense and hard and because the inoculation takes place inside the tube one must look through the medium to try to see if any yeast colonies are visible. These devices are designed primarily to prevent contamination of a swab element once it has picked up targeted inoculum and contain a series of scored break points and sealing gaskets. They are complicated to use and manufacture making them too inconvenient and expensive for home use.
None of the known culturing devices have significantly replaced the traditional smear and culture technique. This is because all the devices achieve a one step culture through increased complexity and cost. All of the described devices are too cumbersome and intimidating for non-professional use. They are too expensive for any but the affluent to purchase, and potentially dangerous. They are unsuitable for use by young people. Brushes, traditional cotton swabs, and the like easily traumatize the delicate mucous membranes of the genito-urinary system. There is no device available that could be used by the average woman for self diagnosis of vaginal yeast infections.
A simple, accurate, and inexpensive device is therefore desired to replace the traditional swab and smear technique and the current one step swab/culture devices. In addition, a device that can be easily adapted for home use for the diagnosis of vaginal yeast infection is greatly desired.